Finely chop the onion and parsley, including the parsley stems.
Step 2 — Make chimichurri
Put 1½ tsp dried oregano*, 1 tbs red wine vinegar and 1 tbs extra virgin olive oil in a large bowl. Add the onion and parsley and season with salt and pepper.
Step 3 — Prep tomato
Cut the tomato into thin wedges, add to the chimichurri and stir to combine.
Step 4 — Cook beef
Separate the beef stir-fry. Heat 20g butter in a large frypan over medium-high heat. Stir-fry the beef for 1-2 mins until browned (beef stir-fry is best with fast cooking; get the pan hot and stick to the short cooking time). Add 3 tsp pepper and garlic seasoning (reduce the seasoning for a milder pepper kick) and cook, stirring, for 1 min or until fragrant. Remove from the pan.
Step 5 — Warm tortillas
Heat a drizzle of olive oil in the same pan over high heat. Warm the tortillas, in batches, for 30 secs each side or until heated through and golden.
Step 6 — Get ready to serve
Spread the tortillas with the aioli and divide among plates. Fill with the spinach, beef and chimichurri tomato to serve.